Tom,
I'm driving my Demon to a show in Roanoake VA in late June. About 450 mile round trip. Black car, black interior, 4 speed with 3:55 gears, 12.5 mpg with a 408 stroker, 2-60 AC (2 windows open at 60 mph). I'm doing it because I can and I want to do it before I can't, but I understand your concern.